After a second place finish in South Carolina's Republican primary, Marco Rubio laughed off a suggestion by Donald Trump that the Florida senator may not be eligible to run for president.

“I’m gonna spend zero time on his interpretation of the Constitution with regards to eligibility and I’m gonna spend all my time talking about what this campaign should be about,” Rubio said Sunday on ABC’s "This Week."

On Saturday Trump retweeted a Twitter user's claim that Rubio is ineligible to be president. When asked about the retweet, Trump said in a separate interview on "This Week" he had never looked into Rubio's eligibility and was only starting a dialogue.

“This is a pattern, this is a game he plays," said Rubio. "He says something that’s edgy and outrageous, and then the media flocks and covers that and then no one else can get any coverage on anything else.”

Rubio argued that Trump was able to dominate media coverage while there were still 15 people running for the nomination, but as the race narrows, “that’s not gonna work anymore.”

“We need to remember that over 70 percent of Republicans nationally have basically said, 'We're not voting for Donald Trump,'” he said.

Rubio also knocked Trump for not exhibiting much knowledge of foreign policy.

“To say, ‘I’m just gonna surround myself with really smart people,’ you know, that’s not enough,” Rubio said. “You yourself have to make judgments, you have to understand these things.”

Rubio added the world would not wait until the new president “catches up” before it starts testing the United States.

Rubio also denied a Huffington Post report alleging former Republican presidential nominee Mitt Romney was set to endorse him soon.

“I’ve spoken to Governor Romney. He’s not set to endorse me and if he were, we wouldn’t be announcing on the Huffington Post,” he said. "I would love to have his endorsement but there’s nothing forthcoming today or in the days to come -- as far as I know.”